This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal is to design and implement multidisciplinary clinical and translational investigations to maximize functional outcome and reduce the risk for post-traumatic osteoarthritis-OA in persons with knee injury. The investigator will gain skills in conducting clinical trials, assessing articular cartilage morphology with magnetic resonance imaging- MRI, and performing biochemical analysis of articular cartilage and inflammation biomarkers to become uniquely cross-trained and able to undertake a comprehensive approach to studying knee rehabilitation. The Primary Aim of the research plan is to determine the effect of intensive quadriceps strengthening on functional outcome and articular cartilage structure after meniscectomy. The Secondary Aim is to examine the association of post-meniscectomy quadriceps strength deficits with lower extremity loading symmetry and the extent of knee inflammation. After baseline testing, 54 subjects with a meniscectomy will be randomly assigned to a 6-week standard rehabilitation program or standard rehabilitation augmented with intensive quadriceps strengthening- high-intensity neuromuscular electrical stimulation and eccentric exercise. Subjects will be re-assessed 7 weeks and 1 year after treatment group assignment. Groups will be compared for differences in self-reported knee function, and in percent loss of tibial cartilage volume on MRI scans from baseline to 1 year. Quadriceps strength deficits will be correlated with peak vertical ground reaction force symmetry during functional activities, and with levels of inflammatory cytokines, TNF-alpha and IL-1beta, in synovial fluid.